PROSTATE GLA1S 7 D. 



147 



vein of the penis, and behind with branches 

 terminating in the internal iliac vein. Many 

 branches of the prostatic venous plexus are 

 necessarily divided in the lateral operation for 

 the stone ; and in old persons, from their in- 

 creased size, they occasionally pour out so 

 large a quantity of blood as to endanger the 

 life of the patient. They often contain cal- 

 culous concretions, to which the term phle- 

 bolithes has been given. The following is the 

 mode of connection between the prostate and 

 the coats of the bladder ; the mucous coat is 

 of course continuous from the bladder to the 

 urethra ; the submucous cellular coat is firmly 

 adherent to the capsule of the gland, whilst 

 the inferior fibres of the detrusor urinae are 

 arranged thus, the longitudinal fibres split into 

 two layers, one, the thickest, adheres to the 

 submucous cellular coat of the bladder just 

 behind the prostate ; and the other, thin and 

 indistinct, is implanted into the base of the 

 gland itself. Harrison has described a long, 

 delicate, and distinct band of muscular fibres 

 as entering the notch in the base of the gland, 

 beneath the uvula vesicae and middle lobe, into 

 which it is sometimes inserted ; but it can 

 frequently be traced nearly an inch further to 

 be inserted into the veru montanum.* lean- 

 not satisfy myself of the existence of any 

 muscular fibres at the under surface of the 

 prostate. On either side of the gland we 

 perceive a muscle, the levntor prostates. It is 

 frequently confounded with the anterior edge 

 of the levator ani, from which however it is 

 occasionally separated by a layer of cellu- 

 lar tissue. It arises from the posterior part 

 of the symphysis pubis by a tendinous slip, 

 and its origin extends for a short distance 

 backwards from the anterior true ligament of 

 the bladder of the corresponding side ; as it 

 descends, its fibres spread out over the side 

 of the prostate, and are inserted into the 

 under part of its capsule j its use is to sup- 

 port the gland, and by compressing it laterally 

 to assist in the evacuation of its ducts. The 

 prostate rests on the anterior surface of the 

 rectum, a thin layer of fascia passing under- 

 neath the gland and the vesiculae seminales. 

 Behind the prostate are the vesiculae, which 

 diverge from each other as they recede, and 

 are in front received into the interval between 

 the lateral lobes, their anterior extremities are 

 placed beneath the third lobe ; the vasa defe- 

 rentia run on their inner side, and the common 

 ejaculatory ducts pass upwards in a curved 

 direction, between the lateral and middle lobes, 

 to terminate by the side of the sinus pocu- 

 laris. 



The anterior surface, which is grooved by 

 a shallow longitudinal depression, is attached 

 to the back part of the symphysis pubis on 

 either side by two ligamentous or tendinous 

 bands, which are continuous with the cap- 

 sule of the gland below, and above with the 

 true anterior ligaments of the bladder ; 



* See Art. BLADDER, vol. i. p. 381. ; 'and for de- 

 scription of the arrangement of the circular fibres, 

 see the same article. 



they are termed the ligamenta pubo-prosta- 

 tica media et later al ia ; they serve to support 



Fig. 101. 



a, bladder ; b, section of the middle lobe of the pros-* 

 tate ; c, left vas ejaculatorium ; d, left vas deferens. 



the prostate and sling it to the pubis, thus 

 contributing to the support of the neck of the 

 bladder. The posterior surface of the pros- 

 tate is smooth and is traversed by a longitudi- 

 nal depression, at the bottom of which two 

 smaller grooves are visible, inclining towards 

 each other in front, they bound two sides of 

 a small triangular portion of the gland ; this 

 is the under surface of the third lobe, on 

 either side of which a vas ejaculatorium takes 

 its course. 



The prostate is surrounded by a dense 

 capsule derived from the vesical fascia; this 

 gives it a complete investment, and adheres so 

 firmly to the tissue of the gland as to be 

 separated from it with great difficulty. It is 

 divisible into two layers,, between which the 

 prostatic plexus of veins runs. The gland 

 itself is of a lightish brown colour, of a fleshy 

 feel, and when cut it offers the resistance ot 

 soft cartilage : it is one of the firmest glands 

 in the body. It is principally formed of two 

 lateral lobes, a right and a left, of equal size in 

 the healthy condition, of an ovoid shape, with 

 their long axes from before backwards ; they 

 diverge from each other behind, leaving an in- 

 terval between them, already mentioned; the 

 lateral lobes are connected together beneath 

 the urethra by an isthmus of variable depth 

 and breadth. Between the two lateral lobes, 

 which make up the bulk of the gland, we find 

 the middle or third lobe. The name of Sir 

 Everard Home is usually associated with the 

 description of this lobe. Although not the dis- 

 coverer of it, he gave the first full description 

 of it. Mr. (now Sir Benjamin) Brodie made 

 dissections of it under Home's direction ; in 

 the first subject in which it was examined, it 

 appeared as a distinct gland, resembling Cow- 

 per's gland in size and shape ; but in the ex- 

 amination of this body in five different subjects, 

 the appearance was not the same in any two 

 of them. The following is the account given 

 by Home of what he considers the most 

 natural condition of this part of the prostate ; 

 " On turning off the vasa deferentia and 

 vesiculae seminales, exactly in the middle of 

 the sulcus, between the two lateral portions of 

 the prostate gland, there was a round, pro- 



L 2 



